In various industries, it is necessary to use many chemicals in the manufacturing process. For example, in the semiconductor industry, some fifteen to twenty liquid chemicals are typically stored in adjacent fifty-gallon drums from which they are dispensed during the manufacture of the semiconductors. In the usual installation, sets of umbilical delivery lines for various chemicals are suspended above the drums with a particular set dedicated to a particular chemical. Each set of delivery lines is connected to its associated drum by a coupling which has one coupling member on the delivery lines and a second coupling on the drum.
As each drum is emptied during the manufacturing process, a full drum is brought in to replace the empty one. Accordingly, the coupling members must be repeatedly connected and disconnected. Because of the incompatibility of the chemicals, it is critical that each set of delivery lines be connected only to its intended drum to avoid unsafe mixing and undesired contamination. Moreover, to maintain productivity, such connections and disconnections must be made quickly and routinely by production personnel.
To insure correct connection of delivery lines to their intended drums, the known chemical extraction apparatus uses fluid couplings that incorporate matching coding elements on the coupling members. Examples of such fluid couplings and their coding devices are shown and described in the U.S. Pat. No. 4,699,298 to Grant et al. and U.S. Pat. No. 5,108,015 Rauworth et al. A significant disadvantage of these known couplings, however, is that they cannot be as quickly connected and disconnected as is desired. Although referred to as quick-connect couplings, they use threads to establish the connection. Repeated threading and unthreading of couplings over a production run consumes a significant amount of valuable time and also can produce additional delays if the threads become fouled and otherwise fail to mesh properly. Moreover, the coding devices of these known couplings require relative rotation of the coded parts to test for a match and then to make the match or to realize that the coupling members are mismatched.
Fluid couplings that can be connected and disconnected without threading are of course available and are truly quick-connect and -disconnect couplings. Examples of known quick-connect couplings are disclosed in U.S. Pat. No. 4,436,125 to Blenkush and U.S. Pat. No. 5,052,725 to Meyer et al. Such known couplings of this type, however, are not suitable for the chemical extraction industry or other industries where matched connections are mandatory since they make no provision for coding. Moreover, the latching mechanisms used in such known quick-connect couplings do not lend themselves to balanced and dependable two-handed operation by personnel in production processes such as described above.